The proposed research will investigate the nature and extent of chromosomal variation in newly initiated and long-term, stable cell cultures of various tick species. Ticks are major vectors of many pathogen organisms which affect humans and their domestic animals. Tick cell cultures are routinely used in various investigations of the parasitology, virology, and physiology of ticks and the organisms that they carry; despite a general lack of knowledge on the genetics of the cultured cells and how the genetics could effect the investigations. The proposed research will provide the initial investigations of the genetics of tick cell cultures. Emphasis will be placed on dynamic situations where karyotypic variations occur; including aneuploid variants, male/female cells in the same culture, and cells of hybrid origin. All of these variations have been previously identified in tick species and/or cell cultures. Cell culture will provide a consistent source of quality metaphase karyotypic figures for use in the application and further development of chromosome banding techniques. Cytogenetic data will be collected on all of the available establish tick cell lines and as many newly initiated cell lines as possible. Species to be investigated include most species of North American ticks that are known to be major disease vectors. Investigations of each culture will include standard karyology, C-banding, C-banding and silver-staining for NORs. Additional techniques such as G-, Q-, and R-banding, along with various DNA base content fluorescent banding techniques, will be added as they become available. The development of these techniques will be facilitated by the consistency offered from cell culture versus the problems encountered with performing these techniques on gonadal squash preparations. The data will be applied to the poorly understood area of tick genetics and extended into tick biology, physiology, systematics, and biological control systems.